Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Hazard Switch Signal | 2 | 1 | 1 | -- |
Hazard Switch Indicator Signal | 3 | 3 | 4 | -- |
Hazard Switch Ground | -- | 1, 2 | -- | -- |
1. Hazard lamps inoperative 2. Hazard lamps always on 3. Hazard switch indicator inoperative 4. Hazard switch always on | ||||
Circuit/System Description
The hazard flashers may be activated in any power mode. The hazard switch is permanently grounded. When the hazard switch is placed in the ON position, ground is applied through the hazard switch signal circuit to the body control module (BCM). The BCM supplies battery voltage to all turn signal lamps in an ON and OFF duty cycle. When the hazard switch is activated, the BCM sends a serial data message to the instrument cluster requesting both turn signal indicators to be cycled ON and OFF.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Exterior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
Hazard Lamps Malfunction
- Ignition OFF, disconnect the harness connector at the S26 Hazard Warning Switch.
- Ignition OFF, verify a test lamp illuminates between B+ and the ground circuit terminal 3.
- Ignition ON, verify the scan tool Hazard Lamp Switch parameter is Inactive.
- Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground. Verify the scan tool Hazard Lamp Switch parameter is Active.
- If all circuits test normal, replace the S26 Hazard Warning Switch.
| ⇒ | If the test lamp does not illuminate, test the ground circuit for an open/high resistance. |
| ⇒ | If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the K9 Body Control Module (BCM). |
| ⇒ | If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 Body Control Module (BCM). |
Hazard Switch Indicator Malfunction
- Ignition OFF, disconnect the harness connector at the S26 Hazard Warning Switch.
- Ignition OFF, verify a test lamp illuminates between B+ and the ground circuit terminal 3.
- Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground. Verify a test lamp illuminates between the signal circuit terminal 2 and ground in an ON and OFF duty cycle.
- If all circuits test normal, replace the S26 Hazard Warning Switch.
| ⇒ | If the test lamp does not illuminate, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the signal circuit terminal 2 for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 Body Control Module (BCM). |
| ⇒ | If the test lamp does illuminate permanently, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the K9 Body Control Module (BCM). |
Hazard Lamp Indicators Malfunction
Ignition ON, command the All Indicators test ON and OFF with the scan tool, verify both turn signal indicators changes between turn ON and OFF.
| ⇒ | If both turn signal indicators changes between illuminate and not illuminate during the test, replace the K9 Body Control Module (BCM). |
| ⇒ | If one or both turn signal indicators do not illuminate during the test or remain illuminated at all times, replace the P16 Instrument Panel Cluster (IPC). |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM or instrument cluster replacement, setup, and programming |
